Scoble writes something—6,800 writes are kicked off, 1 for each follower. Michael Arrington replies—another 6,600 writes. Jason Calacanis jumps in—another 6,500 writes. Beyond the 19,900 writes, there’s a lot of additional overhead too. You have to hit a DB to figure out who the 19,900 followers are. [...] And here’s the kicker: that giant processing and delivery effort—possibly a combined 100K disk IOs—was caused by 3 users, each just sending one, tiny, 140 char message. How innocent it all seemed.